In a known screw of this kind (JP 5-196 021 A)cutting fins as well as threads are provided in common in the tip area up to the free end of the screw.
In another known screw the cutting edge is formed at a so-called cutting channel, i.e. a notch which continues across the tip area and into the shank of the screw (DE 295 13 571 U1).
Further known is a screw which comprises an abrasive edge zone embodied by a plurality of fins in the region of the screw tip where there is no thread, the fins being oriented in the direction of the longitudinal axis of the screw (DE 195 25 732 A1).
Normal wood screws, especially when being turned to enter into softwood, such as coniferous wood, produce a splitting effect. That is true particularly of screws which have a great diameter. The screws penetrating the wood compact the wood fibers transversely of the direction of the fibers at two diametrically opposed locations of the screw so that frequently the wood suffers cleavage. Thus the cohesion of the wood is deteriorated and, therefore, the retaining force of the screw is diminished.